Welding assembly



July 8, 1947. J, M GoULplNG 2,423,811

v WELDING ASSEMBLY Original FiledAugA, 1942 lI .invento- I v v l JoaephM @uid/ang, @guy L1/ys gether.

Patented July 8, 1947 wELmNGfA'ssEMBLY Joseph M.Goulding, Fairhaven,Mass., assignor toaReverefCopper and-Brass Incorporated, New York," 1N.zY., Ya corporation of .Maryland *originalr application Aumt'i, 1942,serial No;

453,494. Divided and this application September 2,1943, vserialNn.'5oo,915

' My invention relates to welding metals by pressure Ywhile in vtheplastiegcondition, particularly to welding'metai elements inftheVmanufacture' of so-'called vbi-metallic" sheets, strips,- :and the like,the present,applicationrbelng -a division of f my 'pendingyaplzilicationtSer'ial Number 453,494, led August 4, 1942.

The invention,` whichhas among its" objects an improved assemblyofmetalslabsor other metallic elements'having relatively large surfaces to bewelded,`wi11 be ybest understood from the following description whenreadin the light of the accompanying drawings of -exa'mples'oi .such`asi jsembly, while thesc'opeof-the invention will be more particularlypointed out in the Vvappended claims.

In thedrawings;

Fig. l'is an -isometric view-:of according-to the invention;

Figs. 2 and 3 are sections, onV enlarged scales,

anassembly-packet on :the linesfZ-,Z and respectively, 'of ig.v 1;

Fig. 4 illustrates a detail, on an enlarged scale;

11 claims. (cines-187.5)

long', mwhich the steel `is about-0.335 inch `thick cladl withcopperabout 0.04 inch'thick. Y

According to Oneway of practising the invention, a steel slab i istreated thoroughly -to clean Fig. 5 is a plan ofia vblank from whicho'ne .of l adjacent relation thereto. yThe entire assembly 'the coversof the assembly packet according vto Figs. 1 to 4 may be formed; fandFigs. 6 and 7 are sections corresponding to Fig. 3 showing modifiedforms ofthe assembly y packet.

Thepresent invention, without limitation .thereto, is particularlyadapted forusein connection with forming so-called bi-metallic sheetsand strips comprising ironjor steel sheets or strips cladon one or bothsides with another metal such'as copper, or copper'base alloys such ascupronickel and gildingmetal.

Generally speaking, the process is performed f by placing a rather thickslab, flat bar, or the like (for convenience"interminology hereinafter'f and in the appended claims termed a slab) of the n cladding metal onasimilar rather'thick shape of steel, heating the slabsthusassembleduntil they become plastic enough to be welded,l andpassingrthem in such plastic condition between the pressure rolls ofamill for welding them to- The rolls of the milll are effective toelongate'the slabs in rolling direction and thus reduce their thickness.By repeatedly passing the slabs while they are hot between the rolls ofthe mill, strips of considerable length and thin gauge may be formedlFor example, asteelslab its opposite faces v3, say by pickling thosefaces and washing rthem toremove Jalltraces :of the pickling-s'olution,or kby subjecting the faces to grinding operations for rendering themclean and smooth. Not` necessarily, but preferably, these ffaces arethen coated with a flash of copper for yof the cladding metal whichcontact the steel slab also being treated by pickling or grindingthoroughly to clean those surfaces. Over the slabs 5 may then be placedpan-like cover members 1 having side Walls 9, which side walls extendover the-edges of the steel `slab '-inclosely imay then be placed in apress to force` one panlike cover toward the other and the slabs I and 5into intimateA contact, and, while the assembly isA under pressure, theedges of the rims of the covers 24vinches Wide, 48 inches-long, and 3inches thick, upon which is placed a Acopper slab :Annen-.thick and'approximately of the same width and'length as the steel slab, may bethus operated upon to produce a strip about 2 4 inches wide and 36 feetthroughout, their entire extent may be electric welded to the edges ofthe steel slab, rasindicated at Il in Figs. 1, 2 and`3, to hermeticallyseal the joints between them,'this welding operation preferably beingperformedby electric arc deposition vof a metal weldingv rod,

Preferably the slabs 5 of the cladding metal are of slightly shorterlength and narrower width than the steel slab i, as indicated in Figs. 2and 3, to permit any slight creep of the slabs 5 relative to the slab iduring the first rolling pass for welding the slabs together.V The tightfit of the parts consequent-upon the pan-like covers being welded inposition while the packet is under pressure will ordinarily prevent anysliding of the slabs 5 relative to the Vslab vl, but to insurev againstsuch sliding the end portions of the slabs may, if desired, be peggedtogether, say` by use of dowels i3 driven intoy aligned drill holesinthe slabs i and 5, before the pan-like covers are placed in,

'welding `temperature ofthe slabs. Commonly, a

single dowel at each end of the slabs will suffice.

thick, are'formed adjacent the peripheries of the slabs with fringibleportions which will break Y and permit removal of the 4covers duringthev initial'part ci the rolling operation. These frangible portions, asillustrated, are formed by providing. the bottoms ofthe covers' adjacenteach end thereof with a transverse groove' I5, these grooves at each endbeing continued over the adjacent side walls 9 of the covers asindicated at I1 (Fig. 1), while connecting the grooves II are grooves I9extending longitudinally along the side walls 9 lengthwise of the slabs.These grooves I5, II and I9 in cross-section are preferably V- shaped,as illustrated in Fig. 4. The depth of the grooves is not critical solong as they provide a materially diminished cross-section of the bottomand side wallsof the covers. With covers made of inch sheet ironsatisfactory results have been obtained in practice with grooves about0.04 inch deep.

Conveniently` the pan-like covers may be made from sheet iron blanks 2Iin which the grooves I5, I1 and I9 areformed. The blanks may be bent onthe lines 23 and 25 to form pan-shaped covers after cutting out pieces21 between the welded together slabs may be reduced to form conditionthe covers protect the steel slab from oxidizing and scaling, whichscaling if it occurred would prevent the slabs from welding togetherduring-the subsequent welding operation. The heated packetmay then beremoved`from the furnace and passed between the pressure rolls of arollin'g mill to weld the slabs together, and by repeatedly passing thembetween the rolls the long relatively thin strips of the bi-metal.

During the first or second pass of the packet between-therolls of themill the consequent elonlbottom of each cover and the adjacent face o!the slab acts as an insulatinglayer to diminish conduction of heat fromthe slabs) tothe cover, as likewise act the sheet 3| andthe graphitelayer or layers when either is employed between the bending lines 23-and25 and the corners of the p time the rims of the covers'at the coveropenings are being Welded to the steel slab I.A

n To insure'against the bottoms of the covers being welded to the slabs5 they are vpreferably made of unpickled` or black sheet iron or steel,

` the scale on such iron or steel preventing the covers from weldingtothese slabs. Better to insure against this welding, the inner surfacesof the bottoms of the pan-like covers may be coated with colloidalgraphite, say by mixing colloidal graphite `powder'and water to form athicky paste and painting the inner surfaces of l the bottoms of thecovers with such paste. Preferably,` however, to prevent anyirregularities present in the bottoms of the covers from "causingirregularities in the outer faces of the slabs 5 when the packetis-rolled, there are interposed `between those faces and the bottoms ofthe covers smooth sheets 3l of npickled black iron or steel, Y

the sides of which sheets in contact with `the slabs 5, or, if desired,both sides thereof, arepreferably coated with colloidal graphite. Also,Vif desired, the sheets 3| may be of rolled copper-silicon alloy. whichsheets do not necessitate the *use of the colloidal graphite becausehaving thereon a film of silicon oxide they will not weld to either thecovers or the slabs 5 Instead of welding the side Walls 9 of the panlikecovers to the steel slab, such walls may be 0f requisite length to abuteach other and enable them to be welded together as indicated at 33 inFig. '1, or may be slightly shorter, as shown in Fig. 6, to enable themto be welded to both each other and the steel slab, as indicated at'35in Fig. 6.`

After the packet is formed it maybe placed in a furnace and heated tothe welding temperature of the slabs, say to about 18507o F. when theslabs 5 are of copper, at which welding temperature Aall the slabs arein a plastic condition.

During the heating of the packet in the furnace and after it is removedtherefrom in a heated cover and slab 5( Y would be omitted.

The material of the covers at the bottoms of the grooves I5, II and I9consequently ruptures when the slabs areelongated, because thev covers,particularly their bottoms, having somewhat cooled resist elongation tothe extent that the slabs elongate, while the transverse side walls ofthe covers are forced to move the weld metal for securing the covers inposition,-

it being understood that the rolled strips almost always are subjectedtosuch a trimming operation after being rolled, and therefore removingthe remnants of the covers and` the Weld metal in this way involves noadditional'operation.

r In place ofla steel slab, a slab of any other suitable metal may beemployed, as is likewise the case with the cladding metal. Further, whendesiredY but one side of the steelor other base slab may be clad withanother metal, in which case it is necessary to employ but one pan-likecover, which latter may be placed over the slab of cladding metal andbe'welded at the cover opening to the edges of the steel or other'baseslab as shown by Figs. 1, 2 and 3, that'.A is to sa?, in such case oneof'- the covers of these figures Y It'will be observed that in all thesecases, whether the steel or other base slab is to be clad on one or bothsides, the panlike cover or covers employed in substance cause the slabsto be boxed or enclosed in arontainer for excluding `air and gases fromthe area or areas of separation of the slabs.

. invention.

I claimz. v 1'. A welding assembly having a pair of metal slabs insuperimposed welding relation, a sheet metal container enclosing saidslabs, said container having a line-like frangibleportion of reducedthickness adjacent the peripheries kof the slabs adapted'to be rupturedfor separating gation of the slabs upon ythe heated assembly beingsubjected to a rolling operation for effecting welding of the slabs.

4. A welding assembly according to claim 3 inV which the container has agroove extending lengthwise of each edge wall thereof from adjaf centone end wall of the container to the other. and has grooves adjacenteach end wall thereof connecting the end portions of the ilrst mentionedgrooves.

5. A welding assembly according to claim 3 in which the container has agroove extending lengthwise of each edge wall thereof from adjacent oneend wall of the container to the other, and has grooves' adjacent eachend wall thereof connecting the end portions of the flrst men` tionedgrooves, the assembly including an insulating layer between thecontainer and adjacent slab face.

6. A welding assembly having a pair of metal slabs in superimposedwelding relation, a panlike sheet metal cover receiving said slabs, the

peripheral walls of which cover are secured to the end and side edges ofthe slab remote from the bottom of said cover in h'ermetically sealedrela-f tion thereto, said cover adjacent the peripheries of said slabshaving a line-like frangible portion of reduced thickness adapted to beruptured for separating the cover by elongation of the slabs lupon theheated assembly being subjected to a, rolling operation for eiectingwelding of the slabs.

7. A welding assembly according to claim 6 in 4which the peripheralwalls of the pan-like cover are continuously welded at their edges tothe end and side edge surfaces of the slab remote from the bottom of thecover.

8. A welding assembly according to claim 6 in which the frangibleportion of the pan-like cover is formed by a groove extending about thecover adjacent the edge walls of the slabs.

9. A Welding assembly according to claim 6 in which the irangibleportion of the pan-like cover is formed by a groove extending about thecover adjacent the edge walls of the slabs, the assembly including aninsulating layer between the bottom of th'e pan-like cover and adjacentslab face.

10.. A welding assembly having three metal slabs in superimposed weldingrelation for adapting the outer slabs to be welded to opposite facesrespectively of the middle slab, separate panlike sheet metal coversover each of the outer slabs, the peripheral walls of `which covers arecontinuously welded at their edges to the end and side edge surfaces ofthe middle slab, the walls of said covers having line-like frangibleportions of reduced thickness adjacent the end and side edges of saidslabs adapted to be ruptured for separating the covers by elongation ofthe slabs upon the heated assembly being subjected to a n rollbingoperation for effecting welding of the sla s.

11. A welding assembly having three metal slabs in superimposed weldingrelation for adapting the outer slabs to be welded to opposite facesrespectively of the middle slab, separate pan-like sheet metal coversover each of the outer slabs, said pan-like covers being welded to eachother at the cover openings, the walls of said covers having line-likefrangible portions of reduced thickness adjacent the end and side edgesof said slabs adapted to be ruptured for separating the covers byelongation of the slabs upon the heated assembly being subjected to arolling operation for effecting welding of the slabs.

JOSEPH M. GOULDING.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS

